Plant-like ProtistsPlant-like Protists *First ‘plants’*First ‘plants’

General Characteristics:General Characteristics:

• eukaryotic, unicellular to eukaryotic, unicellular to multicellular , diversemulticellular , diverse

• live primarily by live primarily by photosynthesizing and at times photosynthesizing and at times heterotrophically ingesting heterotrophically ingesting

• thrives in all types of aquatic thrives in all types of aquatic environment environment

Euglena spp.

Basic Characteristics of Plant-like Protists

1. Chlorophyll and accessory pigments allow to harvest and use the energy from sunlight

2. Euglenophytes (Euglenophyta) are plant-like protists that have two flagella, but no cell wall

3. About half of dinoflagellates (Pyrrophyta) are photosynthetic; the other half live as heterotrophs

4. Members of the phylum Chrysophyta are a diverse group of plant-like protists that have gold-colored chloroplasts

5. Diatoms (Bacillariophyta) produce thin, delicate cell walls rich in silicon (Si)—the main ingredient in glass

Euglenophyta•Euglenoids (type specimen Euglena); with paramylon oils

•Chlorophyll a, b, and c, accessory pigments include carotenoids

•No cell wall, has flexible proteinaceous pellicle

•When grown in the dark, Euglena’s chloroplasts disappear and it becomes heterotrophic; chloroplasts reappear upon exposure to light; 2 flagella

Model Reproduction for Protists

Euglena

Pyrrophyta / Dinoflagellata •Fire Protists (Pyrodinium bahamense var. compressum); with starch and oils

•Chlorophyll a and c, accessory pigments include carotenoids

•Has cell plates of cellulose and silica

•Some forms are bioluminescent; colorful blooms form red tides (HAB’s); 2 flagella

Structure

Pyrodinium

Chrysophyta•Golden Protists (Peroniella; Diaphanoeca); with chrysolaminarin oils

•Chlorophyll a and c, accessory pigments include high carotenoids

•Cell wall has pectin compounds with siliceous materials

•With flagella (1-2) while some groups are aggregated

•Golden colored chloroplasts

StructureBacillariophyta•Diatoms (Navicula; Synedra); with high oil content

•Chlorophyll a and c, accessory pigments include high carotenoids

•Siliceous in nature

•Non-motile or with pseudopodia

•Diatomaceous earth; glasslike, ornate shells in two halves; often mixed with Chrysophyta